The objective of this proposal is to correlate morphologic abnormalities in excised human lungs from primarily young (less than 40 years of age) asymptomatic individuals with no known lung disease, with test of early chronic obstructive pulmonary disease (COPD). Postmortem physiology tests such as maximal expiratory flow volume curves (MEFV), closing volume (CV), maximal mid expiratory flow (FEF 25-75%) will be obtained from excised human lungs as well as static pressure volume curves, saline pressure volume curves and central and peripheral airway resistance measurements and FEV1 and FVC vaules. The physiologic data will be correlated with careful morphometric measurements of whole lung anatomy. This study will established the anatomic basis for test commonly believed to identify "small airway disease". The detailed functional assessment of relatively young human lungs will add to our knowledge of the significance of mild or early lesions of airways and alveoli.